KONDUROS,
J.,: This is an appeal of a workers'
compensation case arising from Claude Potter's compensable injuries, which
originated from a slip and fall during his employment with Spartanburg School
District 7 (School District). The Appellate Panel found that although Potter
did suffer a psychological overlay from his injury, he did not sustain any
permanent partial disability as a result of the psychological overlay, and the
circuit court affirmed. Potter raises several issues on appeal, claiming the
circuit court erred in affirming the following findings: (1) Potter did not
suffer any "physical brain damage" causally related to the accident;
(2) the only body part with resulting impairment from the accident is the right
leg; (3) Potter has not suffered a psychological/mental injury; and (4) Potter
has not suffered permanent and total disability. We affirm.

FACTS

On December 19, 2003, Potter
was performing maintenance on a heating ventilation and air conditioning (HVAC)
system located on the roof of a building for the School District. While
securing a ladder, Potter fell approximately twelve to fourteen feet landing on
asphalt and losing consciousness for a few minutes. He fractured his right
femur with "minimal displacement" and sustained a small cut above his
eye. Potter's right leg was surgically repaired and a few stitches were used
to treat the cut above his eye. The computerized tomography (CT) scan of his
head on the day of the fall showed a "small amount of supratentorial blood."
A second CT scan, taken a few days later, revealed no new problems and the
previous swelling and pressure had subsided. The School District began paying
Potter weekly temporary total disability benefits and provided medical care.

On
November 23, 2004, Potter underwent a neurological consultation. The
neurologist, Dr. Thomas A. Collings, found Potter's reported problems with disequilibrium
were probably not related to his fall, and the vertigo and mild head injury had
resolved itself. His treating physician, Dr. Mark D. Visk, evaluated Potter on
December 16, 2004, and assigned him a twenty percent permanent impairment to
the right leg and discharged him from active care.Potter had an
independent medical evaluation in May 2005. The evaluator provided no
assessment of Potter's mental status, but found he had a twenty-four percent
whole person impairment related to his shoulder, leg, and lower back. In June
2005, Potter received a neuropsychological evaluation from Dr. Randolph Waid, a
licensed clinical psychologist. Dr. Waid noted Potter's injuries included "cognitive
disorder residuals of traumatic brain injury with interfering effects of pain,
sleep disturbance, and fatigue." He recommended Potter receive
psychiatric evaluation and treatment to manage Potter's "sleep
disturbance, mood labiality, as well as depression," along with a course
of psychological counseling to develop "affective compensatory strategies
and antidepressants."Potter's attorney referred him to Dr.
Collings for another evaluation in September 2005. After an examination and a
review of previous medical reports, Dr. Collings opined: "I do not feel
that Mr. Potter has any significant ongoing neurologic difficulty from the fall
on 12/ 18/ 03."

On January 6, 2006, Potter filed a Form 50 alleging he
sustained compensable injuries to his "brain, shoulder, back, hip, leg,
and head" when he fell from the ladder. By consent order, the parties
agreed for Potter to be referred to Dr. David Tollison for psychological evaluation
and treatment, which began on June 20, 2006, and continued until March 14,
2007. During the course of treatment, the School District filed a Form 21
requesting a hearing to determine the amount of compensation to be paid to
Potter.Potter was released by Dr. Tollison in March 2007 at psychological
maximum medical improvement and told to return if needed.On August 30,
2007, the School District denied Potter sustained any compensable permanent
brain damage or that Potter was permanently and totally disabled.

The single commissioner held
an evidentiary hearing on December 4, 2007, and filed an order on January 8,
2008, holding: (1) Potter sustained a compensable injury by accident to his
right leg; (2) Potter reached maximum medical improvement with a thirty percent
partial disability to the right leg; (3) Potter was not disabled from his job
because of his injuries; and (4) he did not suffer any physical brain damage causally
related to the admitted accident. Citing McLeod v. Piggly Wiggly Co., 280
S.C. 466, 471, 313 S.E.2d 38, 41 (Ct. App. 1984), the order noted that Dr. Waid
is a clinical psychologist, not a neurosurgeon or a medical doctor, and his
opinion "concerning alleged brain damage is beyond [h]is area of expertise."
Additionally, the order stated "greater weight is given to the opinion of
the treating physician" with respect to Potter's "injuries and body
parts involved."

Potter appealed, and a
majority of the Appellate Panel affirmed the findings and conclusions of the single
commissioner with some additional findings. The Appellate Panel further found
that although Potter did suffer a psychological overlay from his injury, he did
not sustain any permanent partial disability as a result of the psychological
overlay. In his dissent, Commissioner J. Alan Bass disagreed with the findings
that Dr. Waid was unqualified to render an opinion concerning brain damage and that
Potter did not suffer any brain damage causally-related to the admitted
accident. Potter appealed to the circuit court. The circuit court found
substantial evidence in the record supported the specific findings of fact made
by the Appellate Panel and the decision was not affected by an error of law; therefore,
the circuit court affirmed the findings and conclusions of the Appellate Panel.
This appeal followed.

STANDARD OF REVIEW

The South
Carolina Administrative Procedures Act establishes the substantial evidence
standard for judicial review of decisions by the Commission. S.C. Code Ann. §
1-23-380 (Supp. 2010); Lark v. Bi-Lo, Inc., 276 S.C. 130, 134-35, 276
S.E.2d 304, 306 (1981). Under the substantial evidence standard of review,
this court may not "substitute its judgment for that of the Commission as
to the weight of the evidence on questions of fact, but may reverse where the
decision is affected by an error of law." Stone v. Traylor Bros., 360
S.C. 271, 274, 600 S.E.2d 551, 552 (Ct. App. 2004). "Substantial evidence
is not a mere scintilla of evidence, nor the evidence viewed blindly from one
side of the case, but is evidence which, considering the record as a whole,
would allow reasonable minds to reach the conclusions the administrative agency
reached in order to justify its actions." Brought v. S. of the Border,
336 S.C. 488, 495, 520 S.E.2d 634, 637 (Ct. App. 1999). In workers' compensation cases, the Appellate
Panel is the ultimate fact finder. Shealy v. Aiken Cnty, 341 S.C. 448,
455, 535 S.E.2d 438, 442 (2000). The Appellate Panel is reserved the task of
assessing the credibility of the witnesses and the weight to be accorded
evidence. Id.

LAW/ANALYSIS

I. Physical
Brain Damages Causally Related to the Accident

Potter argues the circuit
court erred in affirming the Appellate Panel's finding that he did not suffer
any physical brain damage causally related to the accident, based on the Appellate
Panel's misinterpretation of McLeod v. Piggly Wiggly Co., and ignoring Tiller
v. National Health Care Center, 334 S.C. 333, 513 S.E.2d 843 (1999).
Potter suggests Tiller stands for the proposition that medical evidence
is not required in workers' compensation claims, even in medically complex
cases, thus he is entitled to a determination of physical brain damage based on
the medical testimony presented to the Appellate Panel. We disagree.

The Appellate Panel is given
discretion to weigh and consider all the evidence, both lay and expert, when
deciding whether causation has been established. Ballenger v. S. Worsted
Corp., 209 S.C. 463, 467, 40 S.E.2d 681, 685 (1946); Tiller, 334
S.C. at 340, 513 S.E.2d at 846. Thus, while medical testimony is entitled to
great respect, the fact finder may disregard it if other competent evidence is
presented. Id. Expert
medical testimony is intended to aid the Appellate Panel in coming to the
correct conclusion. Corbin v. Kohler Co., 351 S.C. 613, 624, 571 S.E.2d
92, 98 (Ct. App. 2002) (citing Tiller, 334 S.C. at 340, 513 S.E.2d at
846). The final determination of witness
credibility and the weight to be accorded evidence is reserved to the Appellate
Panel. Shealy v. Aiken County, 341 S.C. 448, 455, 535 S.E.2d 438, 442
(2000).

The Appellate Panel, as the
ultimate fact finder, was within its discretion to rely on McLeod in
determining the weight Dr. Waid's opinion should be afforded. McLeod provides the Appellate Panel with the ability to ascertain the proficiency of
an expert and to decide whether a "higher degree of expertise" is
needed regarding an award. 280 S.C. at 471, 313 S.E.2d at 41 (holding the
award should be remanded for redetermination when an alleged defect and injury
sustained by the claimant concerned a complicated area of the body requiring a
higher degree of expertise than provided to the Appellate Panel). In this
case, Dr. Waid's opinion, as a clinical psychologist, was reviewed and given a
lesser weight due to the Appellate Panel's evaluation of Waid's opinion
concerning alleged brain damage based on his expertise presented to the
Appellate Panel.

The Appellate Panel's
reliance on McLeod does not disregard Tiller. Tiller allows Dr. Waid's opinion to be taken into consideration by the Appellate Panel
as it weighs and considers all the evidence, both lay and expert, when
determining whether causation has been established. While medical testimony is
entitled to great respect, the Appellate Panel may disregard it if the record
contains other competent evidence. Id. Nor is the Appellate Panel
bound by the opinion of medical experts. Sanders v. MeadWestvaco Corp.,
371 S.C. 284, 292, 638 S.E.2d 66, 71 (Ct. App. 2006). In this case, the
Appellate Panel was presented with
medical evidence from Potter's emergency room physician, Potter's primary
physician, a neurologist, and a psychologist. The Appellate Panel committed no error of law by relying on McLeod in its assessment of Dr. Waid's credibility and the weight to afford his
opinion, as it made its factual findings regarding physical brain damage.
Furthermore, "'it is not for this court to balance objective against
subjective findings of medical witnesses, or to weigh the testimony of one
witness against that of another.' That function belongs to the Appellate Panel
alone." Id. (quoting Roper v. Kimbrell's of Greenville, 231
S.C. 453, 461, 99 S.E.2d 52, 57 (1957)). We therefore affirm.

II. Remaining Issues

The remaining issues have
been abandoned by Potter because he fails to cite any statute, rule, or legal
authority for the three issues in his brief. An issue is deemed abandoned if
the argument in the brief is not supported by authority or is only conclusory. SeeIn the Matter of the Care & Treatment of McCracken, 346 S.C. 87, 92-3,
551 S.E.2d 235, 238-39 (2001) (finding issues were abandoned because there was
no specific legal ground upon which the court could rely); see alsoPack
v. S.C. Dep't of Transp., 381 S.C. 526, 532, 673 S.E.2d 461, 464 (Ct. App.
2009) (holding appellant abandoned issue when she cited no legal authority to
support her argument). While Potter's brief suggests other facts that could
have been considered by the Appellate Panel, he gives this court no substantive
legal authority upon which to rely. Accordingly, these issues are abandoned.

CONCLUSION

The decision of the circuit
court affirming the Appellate Panel's findings
of fact and conclusions of law is